Vacuum-pump system



J. W. CASE Feb. 5, 1929.

VACUUM PUMP SYSTEM Filed Jan. 28, 1927 Inve'ntov. James W. Case,

His Attorney.

Patented Feb. 5, 19 29. I I UNITED STAT-ES JAMES W. CASE, OF

"-omraNY, A oonronanon or NEwYonx.

PATENT OFFICE.

vacuum-rum? sYs'rEM.

Application filed January 28, 1927. Serial No. 184,343.

'My invention relates to vacuum pump systems, such as those used to maintain avacuum within the tank of a mercury arc rectifier, and has for its principal ob ect the provision of an improved apparatus for controlling the connection between the vacuum pump and the evacuated tank. g

In'the operation of vacuum pump systems comprising a valve connected between a vacu-' um pump and a vessel wherein a vacuum is to. be produced or maintained, It 1s desirable that the valve be controlled to open the connection between the vessel and pump only when the pump is operating at or above apredetermined speed. In accordance with my invention, this result is produced by a control'apparatus comprising a torsion spring arranged to close the valve, and a fluid pressure device which operates to open the valve in the appended claims.

against the torsion of the spring when the 'oil' or the like, contained in a vessel 3, and

which is provided with a shaft 4, an outlet conduit 5 and an inlet conduit 6 comprislng a valve-7. The operation of the'valve 7 1s controlled by an apparatus comprising an.

auxiliary pump 8, a fluid pressure device 9 and a torsion spring 10 which surrounds the stem of the valve 7 and is adjusted to ma ntain this valve in its closed position when the pumps 1 and 8 are not operating, or areoperating below a predetermined speed. Any suitable means, such as a disk 11 fixed to the stem of the valve 7 and provided with a plurality of openings arranged to receive one end of the spring 1O, ma be provided for permitting adjustment of the valve stem to any desired position.

The fluid pressure device 9 is provided with a shaft-12 which is fixed to the stem of the valve 7, with a casing 13 having diametrically opposed openings 14 and 15 and a bipartite partition 16 which engages, but is not fixed to, the shaft 12, and with rotatable invention will be better understood fins 17 which are fixed to the shaft 12 and engagethe inner surface of the casing 13 at their outer ends. It will he observed that the casing 13 is connected to the pump 8 through a conduit 18 provided with prongs 19 and 20, and that a by-pass valve 21 is provided for adjusting the positionwhich the fins 17 assume at any given speed ofthe pumps 1 and 8.

The operation of the apparatus will be readily understood without detailed explana tion. Assuming the pumpsl and 8 to be at rest, the valve 7 is closed and the various parts of the apparatus are in their illustrated posit1ons.- When the pump is accelerated to a SCHENECTADY, NEW YORK, ASSI GNOB TO GENERAL ELECTRIC predetermined speed, however, the fins 17 are forced into the position indicated by dotted lines in 2, thus opening the valve 7 and maintalning it open so long as the pump 8 o crates with suflicient pressure to force't e liquid through the orifices 14 and 15 against the tension of the spring 10. Asthe speed of the pumps '1 and 8 decreases, the valve 7.

is operated to its closed position, and the leakage of gas or liquid into the evacuated vessel through the conduit 6 is prevented.

The embodiment of the invention illustrated and described herein has been selected for the purpose of clearly setting forth the principles involved. It will be apparent, however, that the invention is susceptible of being modified to meet the different conditions encountered in its use, and I, therefore,

aim to cover by the appended claims all modifications within the true spirit'andscope of my invention.

What I claim as new, and desire tosecure by Letters Patent of the United States, is:

1. The combination of a vacuum pump provided with an inlet valve, a torsion spring arranged to maintain said valve in its closed position, and fluid pressure means arranged to open said valve against the torque of said spring when the speed of said pump attains a predetermined value.

2. The combination of a vacuum pump .provided with an inlet valve, a torsion spring arranged to maintain said valve in its closed position, a fluid .pressure devlce comprising a shaft coupled to the stem of said valve and arranged to rotate said valve against the torque of said spring, and means arranged to sup ly fluid to said device at a pressure which is e endent on the s eed of said pump.

3. The combination o a vacuum pump provided with an inlet valve, a torsion spring 4. The combination of a vacuum pump provided with an inlet valve, a torslon sprlng arranged to maintain said valve in its closed position, and a fluid pressure device compris ing a. casing having openings, abipartite partition within said casing between said openings, a rotatable member fixed to the stem of said valve and arranged to be held between said openings by the torque of said spring, and means. operable in accordance with the speed of said pump whereby said rotatable member may be moved against the torque of said spring into alinement with said openmgs.

In witness whereof, I have hereunto set my hand this 26th day of January, 1927.

JAMES W. CASE. 

